banan-os/userspace/image/main.cpp

87 lines
1.9 KiB
C++

#include <LibImage/Image.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/framebuffer.h>
#include <sys/mman.h>
#include <unistd.h>
void render_to_framebuffer(const LibImage::Image& image)
{
int fd = open("/dev/fb0", O_RDWR);
if (fd == -1)
{
perror("open");
exit(1);
}
framebuffer_info_t fb_info;
if (pread(fd, &fb_info, sizeof(fb_info), -1) == -1)
{
perror("pread");
exit(1);
}
ASSERT(BANAN_FB_BPP == 24 || BANAN_FB_BPP == 32);
size_t mmap_size = fb_info.height * fb_info.width * BANAN_FB_BPP / 8;
void* mmap_addr = mmap(nullptr, mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (mmap_addr == MAP_FAILED)
{
perror("mmap");
exit(1);
}
uint8_t* u8_fb = reinterpret_cast<uint8_t*>(mmap_addr);
const auto& bitmap = image.bitmap();
for (uint64_t y = 0; y < BAN::Math::min<uint64_t>(image.height(), fb_info.height); y++)
{
for (uint64_t x = 0; x < BAN::Math::min<uint64_t>(image.width(), fb_info.width); x++)
{
u8_fb[(y * fb_info.width + x) * BANAN_FB_BPP / 8 + 0] = bitmap[y * image.width() + x].r;
u8_fb[(y * fb_info.width + x) * BANAN_FB_BPP / 8 + 1] = bitmap[y * image.width() + x].g;
u8_fb[(y * fb_info.width + x) * BANAN_FB_BPP / 8 + 2] = bitmap[y * image.width() + x].b;
if constexpr(BANAN_FB_BPP == 32)
u8_fb[(y * fb_info.width + x) * BANAN_FB_BPP / 8 + 3] = bitmap[y * image.width() + x].a;
}
}
if (msync(mmap_addr, mmap_size, MS_SYNC) == -1)
{
perror("msync");
exit(1);
}
munmap(mmap_addr, mmap_size);
close(fd);
}
int usage(char* arg0, int ret)
{
FILE* out = (ret == 0) ? stdout : stderr;
fprintf(out, "usage: %s IMAGE_PATH\n", arg0);
return ret;
}
int main(int argc, char** argv)
{
if (argc != 2)
return usage(argv[0], 1);
auto image_or_error = LibImage::Image::load_from_file(argv[1]);
if (image_or_error.is_error())
return 1;
auto image = image_or_error.release_value();
ASSERT(image);
render_to_framebuffer(*image);
for (;;)
sleep(1);
return 0;
}